Casing for electric transformers and the like



July 24, 1928. I 1,678,090

0. WEHRLE CASING FOR ELECTRIC TRANSFORMERS AND was LIKE Filed April 24, 1926 v the welded seams.

Patented .luly 24, 1928.

UNITED. STATES PATENT OFFICE.

orro WEHRLE, or EMMENDINGEN, GERMANY.

CASING FOR ELECTRIC TRANSFORMERS AND THE LIKE.

Application filed April 24, 1926, Serial No. 104,343, and in Germany May 9, 1925.

This invention relates to an oil container with corrugated sheet metal walls, mainly intended for a vessel to contain a transformer. In the manufacture of such oil vessels, in which the corrugated sheet metal casing is joined at the bottom to a trough and on top to a cover frame, provision has simultaneously to be made for efiicientheat interchange, simplicity of construction, resistance to external and internal stresses and absolute liquid-tightness. This multiplicity of requirements creates especial ditliculties in respect to the junction of the closed ends of the corrugated sheet metal casing on top with the cover frame and at the bottom with the trough. The present invention relates thereforeto an arrangement in this respect, in which all the above mentioned ditliculties are simultaneously overcome in an efiieient manner. The feature of the invention consists in the sheet metal cover closing the corrugated sheet metal casing at the end, being bent as afluting (curved or U-shaped) at its inwardly extending border and the bent back border of the sheet metal fiuting being welded to a correspondingly extending border of the cover frame or the trough. The employment of the fluted bend involves on the one hand the advantage that such bend provides an elastic equalization member, by means of which ununiform expansion under heat within the vessel, which occurs considerably, is allowed for; on the other hand in this construction of the borders of the sheet metal end covers, the welded scams, by means of which such borders are joined to the cover frame and trough re spectively, are relieved of load, inasmuch as the corrugated sheet metal casing rests with the lower border on the trough and the cover rests on the upper border, whereas otherwise the entire weight would hang on Moreover this arrangement permits the possibility of employing a double weld between. the borders resting on one another, viz., a weld extending along the outer edge, serving merely for liquid tightness, and a securing weld located inside the vessel. Finally there is the advantage, that the welding seams are well separated from all other situations of welding, whereby the security of the weld is enhanced.

Figs. 1 and 2 show a constructional example of the invention, in which Fig. 1 is a longitudinal section and Fig. 2 a fragmentary section on 22 of Fig. l.

Figs. 3 and 4 show variations of the flutmg.

Figs. 57 show variations of the joint of the corrugated sheet metal casing with the trough.

The corrugated sheet metal casing g is covered by the continuously extending end sheet metal cover f. F inger-like tongues of the cover plate are welded to the individual corrugations. Such cover plate formed from a single piece extends with its unnotched portion inwards beyond the corrugated sheet metal casing. This inwardly extending portion 6 of the plate f is, bent upwards as a fluting. Theprofile of the fluting can be either semi-circular, as shown in Fig. 1 or partially with a straight wall, more U- shaped, as for instance shown in Figs. 3 and 4. .The lower correspondingly wide end surface 25 of the cover frame a rests on the sheet metal fluting e and is joined thereto by a double weld. The outer edges are united by a weld seam c, which chiefly serves for liquid-tightness and can without difliculty be added to or renewed; along the inner joint is the weld d, which mainly serves as a securing weld.

The bottom covering of the corrugated sheet met-a1 consists of a similarly shaped end plate h, the unnotched inwardly extending portion a of which is doubly bent. The bent back border j rests on the correspondingly wide border is of the trough and is united thereto by double welding, an outer weld m and an inner n.

It is not absolutely necessary to employ two connections, the upper to the cover frame and the lower to the trough, formed both in the described manner. The manner of making the upper connection to the cover frame illustrated in Figs. 1-3 can be employed with another kind of lower connection to the trough, for instance in conjunction with any of the trough connections shown in Figs. 5-7. Such a trough'connection is of particular utilit with a trough with a U-shaped border. is shown in Fig. 5 in such case the simply downwardly bent border 0 of the bottom continuous cover plate 71, is welded to the outer border 1' of the trough by means of the double weld p, 9.

With such a method of connection the ad vantage of an elastic fluting is not provided at the bottom, but the welding remains of ample strength, as it is double and well separated from other welds. Similar contric transformers, a corrugated casin a border.

plate secured to and closing the tops of the corrugations of said casing and having an outwardly bent inner border, and a' cover frame welded to said outwardly bent border.

2. In an oil conta'tner especially for electric transformers, a corrugated casing, a plate secured to and closing the tops of the corrugations of said casing and having an outwardly bent inner border, and a cover I frame welded by separate welds both to the edge and to the bend of said outwardly bent 3. In an oil container especially for electric transformers, a corrugated casing, a plate secured to and-closing the bottoms of the corrugations of said casing and having a bent inner border, and a trough welded to said bent border.

4. In an oil container especially for electric transformers, a corrugated casing, a plate secured to and closing the bottoms of the corrugations of said casing and having a bent inner border, and a trough welded by separate welds both to the edge and to the bend of said bent border.

5. In an oil container especially for electric transformers, a corrugated casing, a plate secured to and closing the bottoms of the corrugations of said casing and having a bent inner border, and a trough having a bent border Welded by separate welds both edge and to to the edge and to the bend of said bent border of the plate.

6. An oil container especially for electric trasformers comprising a corrugated casing,

a platesecured to and closing the tops of the corrugations of said casing and having an outwardly bent inner border, and a cover frame secured to said outwardly bent border.

7 An oil container especially for electric transformers comprising a corrugated casing, a plate secured to and closing the ends of the corrugations of said casing and having a bent border, and a cover frame secured to said bent border.

8. In an oil container especially for electric transformers, a corrugated casing, a plate secured to and closing the bottoms of the corrugations of said casing and having an outwardly bent inner horizontal border, and a trough having a bent horizontal border welded by separate welds both to the edge and to the bend of said bent border of the plate. I

9. In an oil container especially for electric transformers, a corrugated casing, a

plate secured to and closing the tops of the corrugations of said casing and having an outwardly bent inner border, a cover frame welded to said outwardly bent border, a plate secured to and closing the bottoms of the corrugations of said casing and having an outwardly bent inner horizontal border, and atrough having a bent horizontal border Welded by separate Welds both to the the bend of said bent border of the plate.

In testimony whereof I have signed my name to this specification.

OTTO WEHRLE. 

